Door apparatus and control



July 1, 1958 w. T. LITHERLAND 2,841,

DOOR APPARATUS AND CONTROL Filed Aug, 50 19 l VENTOR hwwd 3% C m ATTORNE United States Patent fifice V 19,,

noon APPARATUS AND CONTROL William T. Litherland, Pontiac, hIiciL, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application August 30, 1955, Serial No. 531,527

2 Claims. (Cl. 26847) This invention relates generally to doors and automatic apparatus for opening and closing the doors. The invention refers more particularly to doors of the type that are used on public conveyances, such as railway trains, and is specifically concerned with the doors which connect the main part of the car to the vestibule of the car.

Many controls have been proposed for operating vestibule doors. These controls, however, are complicated and are subject to various defects and deficiencies; for example, many of the doors must be manually opened, other doors require operation of various controls not located near the doorsrequiring the person desiring to pass therethrough to hunt .for the operating mechanism. Quite often the doors are difiicult to open because the controls therefor are subject to frequent failure. Such doors have previously required a substantial amount of maintenance and have been the cause of frequent accidents which in some instances resulted in serious injury.

The present invention has been proposed to provide a door control which is extremely simple to operate, completely safe, and requires the minimum of attention from the standpoint of servicing and repair.

One important object of the invention is to provide a door control which enables the persons using the doors to merely momentarily touch the doors themselves to open them and maintain them open for a predetermined interval after which the doors will automatically close. If, however, any obstruction should remain between the doors as they close, the touching of this obstruction by the doors will immediately cause the doors to again open and again remain open for a predetermined interval.

For further objects and a fuller understandingof this in- V vention reference may be had to the accompanying detailed description and the drawing, in which:

The single figure represents schematically a pair of doors for which the new control is ideally suited, including the door-operating mechanisms and the unique control therefor.

Referring now to the drawing, in the particular example shown, a railway vehicle 2 is provided at one end thereof between the main part of the car and the vestibule with a pair of sliding doors 4 which are suitably hung and guided so as to easily slide apart to provide passage be- .tween the vestibule and the main part of the car. Each of these doors adjacent their abutting edges is provided with a so-called sensitive'e'clge 6. Each of the sensitive edges 6 is diagrammatically shown in a small sectional insert as operative'ly controlling 'a switch indicated by a numeral 8. It should be emphasized at this point that these sensitive edges are a welLknown product readily available on the open market and in. and of themselves form no part of this invention and therefore no further description is deemed necessary with respect thereto other than to say that a slight touching, which is easily regulated for more or less sensitivity, will cause either of the switches 8 to close or open, whichever may be desired. The sensitive edges 6 and switches 8, of course, form important elements of the unique door control and their function in the control will be brought out in detail shortly.

Each of the doors is provided with an actuating link 10 which has one end pivotally attached to the door to approximately its vertical midpoint. Each lever 10 is fulcrurned at a point 12 fixed as by bracket 14 to the main structure of the car. The opposite end 16 of the right-hand link 10, as viewed in the drawing, is pivotally fastened at point 18 to an operating rod 20 which is connected to a conventional air servomotor or piston and cylinder assembly 22. The link 10 for the left-hand door, as viewed in the drawing, has its end 16 connected by means of a rod 24 to a small lever 26 pivoted to the main structure of the car at 28 and connected to the end 16 .of the right-hand lever 10 by means of a link 30. This latter structure interconnects both the right-hand and lefthand levers 10 so that the doors move uniformly together and apart upon appropriate actuation of the cylinder and piston assembly 22. Air is supplied to the opposite sides of the piston of the servomotor 22 by means of a closing solenoid-operated (air magnet) valve 32 and a solenoidoperated opening (air magnet) valve 34 connected to opposite ends of the cylinder of assembly 22. These air magnet valves regulate the supply of air to the cylinder of assembly 22 from a suitable air pressure source via the piping 36. The extent of opening of the doors is limited by the levers 10 abutting suitable cushioned stops 33 provided on the bulkhead separating the vestibule from the main part of the car.

A suitable voltage source such as the battery BAT is provided for operating the electrical portion of the control whose main components include a manually controlled switch SW, a relay 40 having a pair of interlocking switches 42 and 44, a door-control switch 46 having a normally open and a normally closed position, the aforementioned switches 8 operated by the sensitive edges, the solenoid portions of the air valves 32 and 34 and a capacitor 48. The operation of the control is as follows:

The switch SW, it will be observed, has two positions as viewed in the drawing, an upper position and a lower position. When the train is in motion the switch SW will normally be placed in its uppermost position for automatic operation of the doors. Assuming the switch SW to be in this position and someone desires to pass between the doors he would place his hand or finger on one of the sensitive edges as directed by a legend placed thereon. The touching of one of the sensitive edges will cause one of the switches 8 to close. Closure, let us say, of the left-hand switch 8 as viewed in the drawing will enable a current to flow from the negative side of the bat tery through conductors 5t? and 52, the now closed lefthand sensitive edge of switch 8, conductors 54, 56, 58 and 60, through the energizing winding 62 of relay 40 and conductor 64 to ground GR. Energization of the winding 62 of relay 40 will cause its interlocks 42 and 44 -to move from their normally open position to their closed position, that is, from their uppermost position to their lowermost position. Movement of the interlock 44 to its lowermost position will close a holding circuit for the energizing coil 62 of relay 40. This holding circuit may be traced out as follows: Beginning with the negative side of the battery BAT current will flow through conductor 50, conductor 66, conductor 68, the contacts of the door switch 46 in the position shown when the doors are fully closed or only partially opened, conductor 70, the interlock 44 in its lowermost position and conductors 58 and 60, winding 62 of relay 40, and conductor 64 to ground GR. Because of this holding circuit the winding of the relay 40 will remain energized even though the sensitive edges 6 are no longer being touched and this relay will remain energized until the doors are fully opened. The

Since both theopening air magnet 7 closing air magnet, valve 32 are energized at the same door-opening circuit is completed by the upper interlock 42 of the relay 40 moving to its lowermost position as viewed in the drawing so as .to energize the door-opening magnet valve 34. This door-opening circuit includes i the negative side 'of the battery BAT;'conductors;50,- 66; conductor 72; the right-hand upper contact of the switch SW; ,conductor74; the upper interlock. of the relay. 40 f nowin its lowermost'position; conductors76, 78; the

energizing winding .of the doorropening solenoid 34 and to ground GR. Since the relay..40 is held in or. picked 'up,this door-openingsolenoid 34 .will remain energized for a predetermined interval of time is also'believed to be 'a unique feature of this invention since formerly, attempts and the doors will move to their fully open position As theydo so, however, the door-control switch 46, at the :time the doors are fullyzopened, is moved from its lefthand position as viewedfin the drawing out oflengagementwith the lefthandcontact into engagementwith the V 'iright-hand'contact. 1 Movement of switch 46 :away from 'theIeft-hand contactbreaks the holding circuit for the winding 62*of the relay 40. However, because of the presence of the capacitor 48, which is connecte d in parallel (by means of the'conducto'rs 80 and 82) with the winding 62, the relay 40Will remain energized or picked up :until this capacitor isidi'scharged, i. e., for a predetermined interval of time. 'Also, movement of thesdoor-control' switch 46 to its right-hand contact as the doors are fully opened closes the door-closing circuit to thereby energize the solenoid-operated valve 32 which supplies air to the cylinder assembly 22 so as to cause the doors to close.

Beginning with the negative side of the battery BAT current 'may flow through conductors 50, 66, 68; the right-hand .Thislatter circuit may be traced out as follows:

.contact of: door-control switch 46; conductor. 84; air pressure switch 86 which is closed on propermaintenance ofoperating pressure in the air pressure source; conductor "88; the left-hand upper contact of the switch SW as door-control circuit and doors'will remain'in open posi- .tion. With switch in upper position, doorswill close and cir-.

To close doors, place switch SW in.,upper position.

cuit will be returned to automatic operation.

From the foregoing description itmay be appreciated. that a door apparatus and control has been provided U which is extremely simple and which utilizes sensitive.

edges in a unique way'to completely operate the doors from a fully closed or partially. closed position. The use of a capacitor for the purpose of holding the doors open were made to hold such doors open 'by complicated door switches having multiple contacts, etc. V

What I claim is:

1. An electricalcontrol for a door including a sensitive edge having a switch actuated thereby .upon touching and a door-operating linkage comprising first electrical means .,connectedsto said' linkage operable to opensaiddoor,

second electrical means connected-to said linkage operable 7 to. close said door, a voltage source in elect ricalcircuit .a relay energizable by touching ofsaid edge .tdclose said switch, a holding circuit 'for said relay energizable by.

iviewed in the drawing; conductor 90 and the'air magnet valve 32; .thence to ground'GR. i

valve 34 and the time, however, the doors will remain in the fully open position until such time as the'capacitor 48 discharges,

after which relay 40 will drop out and de-energize the switch '46 will return to its left-hand position in contact .with itsleft-hand contact 7 Return of the door-control switch to its left handjposi- V V door-opening *circuit. The door-closing ,circuit then is 7 effective to clojsethe doors at which time the door-control .tion, as viewed in .thedrawing, de-energizes the doorclosing magnet valve 32 and again sets up the holding circuit for relay 48. This action will berepeated when the sensitive edges are touched either in the fullyclosed position or the. partially open position.

If the sensitive .edges are leaned against or touched when the doors are fully opened the doors will continue to remain fully open because of constant energization of the winding 62 of the relay 40. V.

It should also be mentioned that the door is capable of i being permanently held open as, for example, when in the station and passengers are continuously passing through the doors either to disembark fromthe-train or board the train. This may be accomplished by moving the switch SW to its lowermost position as shown in the drawing in which case the door-opening solenoid 34 will be permanently energized by current flowing from the'negative side ofthe battery BAT through conductors 50,66, 72; the right-hand side of switch SW in its iower' 'most position; conductor 78'and solenoid 34 to ground 'GR. Actually, switch SW in lower position is spring loaded .so that when released it returns to a center or ofi position when released. This breaks the'c'omplete with saidswitch and said-electricaldoor-opening'means,

energization of said relay, a door switch in said holding circuit operable by full openingj of said-door to break said holding circuit, a capacitor connected to said source in parallel with the winding of said relay to delay dropping out of said .relayiupon breakage of saidholding-circuit,

said relay including contacts closed-by energizat-ion there- I of in series with contacts on ;said door "switch closable upon full opening of saiddoor to energize said doorclosing means whereby 'saidddor clo'sesupon discharge of said-capacitor. L

2. An electrical control for a door including a sensitive edge having'a switch'actuatedthereby upon touching-and a' door-operating linkage comprising firstelectrical means connected to said linkage operable to open said door, second electrical means connected to said linkage operable to 'close lsaid door, a voltage source in electrical circuit with said switch and said electrical door .opening means, a relay energizable by -touchingof said edge to: close said switch; a holding circu'it for said relay energizable byenergizationeof said relay, a door switch in saidholdingTcircuittoprable.by full opening of said' door to breaks'aid' holding circuitga capacitor connected j to said-source in parallel with the winding of said relay to;delaydropping out of .saidrelay upon breakage of said holdingcirc'uit, said relayjnclu'ding contacts closed by energiza'tion' thereof in series' with'contacts on said door swltchclosablenpon full openingofsaid door to energize said door-closing means whereby said door closes upon discharge "of saidcapacitor, and manually operated switching means between said voltage source and said first electrical means operable to energizesaid first electrical means and hold open said door. V

. References'Citedin the fileFot this patent 

